code: def _scale(x, lb, ub):
      """Scales the values to be normalized to [lb, ub]."""
      return (x - lb) / (ub - lb)
  
file_path: tf-quant-finance/tf_quant_finance/models/hull_white/calibration.py
imports: from typing import Callable, Tuple, Union
  import tensorflow.compat.v2
  from tf_quant_finance import types
  from tf_quant_finance import utils
  from tf_quant_finance.black_scholes import implied_vol
  from tf_quant_finance.black_scholes.implied_vol_utils import UnderlyingDistribution
  from tf_quant_finance.math import make_val_and_grad_fn
  from tf_quant_finance.math import optimizer
  from tf_quant_finance.math import piecewise
  from tf_quant_finance.math import random
  from tf_quant_finance.models.hull_white import cap_floor
  from tf_quant_finance.models.hull_white import swaption
  from tf_quant_finance.rates.analytics import swap
label_desc: Use image node_id 3 for calling a global function with example usage: _scale(x, lb, ub) and returns: unknown